This invention relates to changeable signs, and more particularly to signs displaying changeable characters such as numbers indicating prices.
Changeable signs have long been used in a variety of businesses to advertise the prices of various products or services. Such signs are particularly useful to gasoline service stations for posting the prices of various grades of gasoline. The prices of gasoline fluctuate, requiring frequent updating of the signs. Changeable signs are also used to advertise sales on other products and services offered by the service stations.
A variety of changeable sign boards have been proposed to make updating of the signs as easy as possible. One is a sign board comprising a flat metal or wooden board upon which metal rectangular panels are mounted by means of a hook and eye arrangement, a different metal panel being provided for each number from zero to nine. Other forms of such signs provide for flip-down number panels or insertable numerals, such as disclosed in U.S. Pat. No. 3,074,193 to Munson. One drawback of this form of changeable sign is that ten panels are required to cover all of the variations of each numeral on the sign. A price sign displaying two different prices of gasoline would thus require numerous different panels to cover all the various price possibilities within three digits. Another drawback is that such signs are ordinarily very limiting in terms of format. They cannot be altered at will to display completely different information.
Changeable signs have also been provided in the form of a two-dimensional array or grid of lights which are selectively switched on and off to form a desired number or other character. A variation of this idea, using an array of circular discs, oppositely colored on opposite sides, in openings in a sign board mounted on a magnetically rotatable shaft is disclosed in U.S. Pat. No. 3,365,824 to Winrow. Depending on which sides of the eleents are exposed, different numeric characters are formed. A similar arrangement for forming alphabetic characters is also disclosed in U.S. Pat. No. 1,679,520 to Giroux. In U.S. Pat. No. 4,223,464, Winrow proposes another changeable numeric display in which the rotatable display elements are elongated segments positioned to define vertical and horizontal sides of a figure eight.
U.S. Pat. Nos. 4,115,936 and 4,164,824 to Nidelkoff disclose changeable character signs having elongated shutters mounted for sliding or pivotal movement in openings in a sign board for selectively opening and closing the openings to define segmented numeric characters on the sign board. Discrete magnets are mounted in the handle of each shutter to releasably secure the shutter along the edge of the opening in the sign board in an open or closed position. These shutters are also arranged in a figure eight pattern to form various numerals. U.S. Pat. No. 755,272 similarly provides a changeable sign having an array of hinged elements which are pivoted between open and closed positions to selectively expose or cover surfaces of contrasting color to define various alphanumeric characters.
All of these sign arrangements are susceptible to damage, particularly when placed outside, such as in front of a gasoline service station. These signs are also much more complicated and expensive than desired for many applications. Additionally, none of the foregoing changeable sign structures provide a convenient means for completely changing the information displayed on the signs. All of them are limited in some respect to displaying solely the characters defined by the elements arranged on the face of the sign.
Accordingly, a need remains for a simpler, more versatile, less expensive and more durable form of changeable sign.